O/T passat wont start
Turbo Mini Forums

I recently changed the turbo on a friends 1998 20v passat turbo, i removed the original turbo, sourced him a decent secondhand one and a couple of weeks later fitted the replacement one, once it was all fitted and ready to go i tried to start it, the battery was flat, so out came the jump leads and i tried jumping it from my mini with no luck!

Told him to charge his battery, which he did, and it still wont start!
Went round today to see if anything was obvious, found one thing i forgot to connect, which was the air intake to the turbo! doh!, refitted this and in the process i managed to break the vacume line to the dump valve.

Would these small errors cause it not to start or is it likely to be something else?

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

did you have any diesel or diesel leak off pipes or diesel filter off?

will it start and run if you squirt brake cleaner down the inlet (dot do this to much as its harmfull, but good to rule out compression)

have you left rag's stuffed in any pipes?

didn you have the ignition on when you hooked up your jump leads, or did you wiggle them with the ignition on? if so posibility of a dead ecu. but check al fuzes.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

did you have any diesel or diesel leak off pipes or diesel filter off?

will it start and run if you squirt brake cleaner down the inlet (dot do this to much as its harmfull, but good to rule out compression)

have you left rag's stuffed in any pipes?

didn you have the ignition on when you hooked up your jump leads, or did you wiggle them with the ignition on? if so posibility of a dead ecu. but check al fuzes.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

its a petrol one.
was planning on trying some easy start down the inlet,
definately no rags left in any pipes, and i dont think i had the ignition on when i connected the jump leads...hope i have not killed the ecu.
try to do people favours and it all goes tits up!

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

ah ok, sorry just read passat and turbo and assumed diesel! if you pull the coil out and put a spare sparkplug in it you can check for a spark, dont be tempted to try without as can damage the coils, there pretty sensitive.


did either the cam or crank sensor take a hit or become unplugged? you need both to start.

do you have the crank sensor plugged in to the right plug? (usualy beige on these things) though this is all over the inlet side so cant imagien why youd be faffing with it. could you try unplug the AFM and disconect the boost hose to the inlet and try starting, incase the intercoolers blocked.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

and please charge the battery and use that witha jump if necesary, jumping to a dead battery can cause havoc :)

and mind check all fuzes including in-car ones :) and check if its possible anything is plugged in the wrong place.

Edited by evolotion on 19th Nov, 2009.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

it started! gave the battery a good old charge and it busrt into life!

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

there you go!

make sure the NEW! battery is not on its way out (ie) you have not killed it on trying to strart the engine or it will come back and bite you in a cold snap.

oh bugger! just had a phone call from the owner of this car, apparently it has started making noises similar to the original noise which was a knackered turbo!

the original situation was; turbo removed, it was very worn, found a supposedly good used one, it seemed fine, no excess movement, fitted it, all was good, (once started!) until today!

so, would this be a case of thats what you get when buying used parts?
or could there be another problem causing the turbo to wear?

also would it be possible to remove the inside of the turbo compressor wheel etc and use the car like this?

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

Check oil supply and drain.

would it be ok to do this with the engine running?
eg, slacken the feed bolt off and see if oil leaks out, then slacken the drain bolt off and see if its coming out there.
or is there a better way of checking this?

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

Given this is the same engine as the TT, i'd check the oil pick-up in the sump. Apparently they are prone to blockage - particularly if the oil changes have been neglected. first thing to let go is the turbo apparently.

only way to check this is to drop the sump but should be easy enough

oh. is it an inline engined passat? (like audi layout) if so (as above) itll be the oil pump / pickup. have changed a few of these now. not a plesant job and on some models a special tool is needed as there is no recess in the flywheel to reach the rear sump bolts. you need to drop the front subrame down aswell(you can leave it hanging on the rear 2 bolts) however, would do an oil pressure check and check the oil feed pipe isnt blocked first, as every 1.8T i have done an oil pump on had low oil pressure warning lights on teh dash after a motorway cruise.

and was a result of city driving only, or lack of servicing.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.